4 Channel LED RGBW PWM Controller

This circuit drives LED strips with up to four channels (RGBW).
It supports different color scenes and dimming.
An infrared proximity sensor is used to control the device.

Microcontroller: ATmega48

An ATmega48 is used to control the LED driver. It implements three main tasks:
1. Provide the main logic function with a state machine.
2. Handle user events coming from the infrared proximity sensor.
3. Generate the four PWM signals which are routed to the MOSFETs.

Sensor: TMD26721

For controlling, a IR proximity detection sensor is used: TMD26721.
It is connected via I2C to the microcontroller which reads periodically the proximity values, filters it and detects events.
For prototyping, the sensor was solded "flying" on eight wires:
The chip integrates sending and receiving diodes, so no external optical component is needed.

PCB: fits into aluminium profile

The photos above show the first prototype built on bread board.
The final printed board is designed to fit together with the LED strip into a aluminium profile.

Sources

The source code of this project and the hardware design is closed. If you are interested in it, please contact me.